December 2016, Vol. 243, No. 12

Features

Feds Recommend Safety Measures for Storage Facilities

In the wake of a massive gas leak that occurred Oct. 23, 2015 at the Aliso Canyon Underground Natural Gas Storage facility near Los Angeles, an interagency task force came away with three key recommendations:

• Gas storage operators should begin a rigorous evaluation program to baseline the status of their wells, establish risk management planning and, in most cases, phase out old wells with single-point-of-failure designs.

• More advanced preparation and coordination of emergency response is needed to address possible natural gas leaks in order to mitigate potential health and environmental impacts of leaks when they do occur.

• Power system planners and operators need better understanding of the risks potential gas storage disruptions create for the electric system.

In all, the task force made over 40 recommendations requiring additional actions for the nation’s natural gas storage facilities, which it said will ensure long-term safety and operation. The task force was co-chaired by Franklin Orr, undersecretary for Science and Energy at the DOE, and Marie Therese Dominguez, administrator of the Department of Transportation’s Pipeline and Hazardous Materials Safety Administration (PHMSA).

Other agencies represented were the Department of Transportation (DOT), the Environmental Protection Agency (EPA), the Federal Energy Regulatory Commission (FERC), the Department of Commerce (DOC), the Department of Health and Human Services (HHS), the Department of the Interior (DOI), as well as state and local governments.

According to PHMSA, Ensuring Safe and Reliable Underground Natural Gas Storage is intended to provide guidance to the industry concerning the agency’s phased rule-making process, thereby allowing companies to begin making changes immediately. The 83-page report is divided into a gas storage primer, a review of the Aliso Canyon incident, and observations and recommendations of the task force.

PHMSA plans to issue interim regulations regarding underground natural gas storage in the coming months, incorporating API Recommended Practices 1170 and 1171.

Secretary of Energy Ernest J. Moniz said the task force’s recommendations are designed to help minimize the risk of well failures, reduce health and environmental effects of major leak incidents, and provide a better understanding of energy-reliability implications as the principal research areas associated with natural gas storage facilities.

Report Summary

The task force said while California is still analyzing the root cause of the Aliso Canyon leak, records indicate the well was operated with a single point of failure design – allowing gas to flow through both production tubing and well casing, making the system dependent on a single barrier to contain the gas.

The report found that if a second barrier had been in place, the uncontrolled leak likely could have been avoided. Additionally, the task force found the inspection, monitoring and risk-management program for the well appeared to be inadequate to ensure safety. For example, logs show the majority of wells at the facility had not been recently evaluated for integrity.

Based on these findings and more, the report makes the following key recommendations addressing well integrity issues:

• New wells should be designed so a single point of failure cannot lead to leakage and uncontrolled flow, and except under limited circumstances, natural gas storage operators should phase out single point-of-failure wells.

• Operators should adopt risk-management plans that include a rigorous monitoring program, well integrity evaluation, leakage surveys, mechanical integrity tests and conservative assessment intervals.

• DOE and DOT should conduct a specific and thorough joint study of subsurface safety valves.

Health, Environment

 The report pointed out that following the Aliso Canyon leak, residents of nearby neighborhoods experienced health symptoms consistent with exposures to odorants added to the natural gas, thousands of households were displaced, and about 90,000 metric tons of methane were released from the well.

In order to prevent or mitigate similar health and environmental effects in the event of future leaks, the report’s recommendations included:

• In the event of a natural gas leak large enough to require multiple jurisdictions in the response effort, a “unified command” be formed early so that leaders from each primary response agency can provide clear and consistent communications between agencies and with the public about progress toward controlling the leak and understanding the potential public health implications.

• States and local monitoring agencies should consider establishing an emergency air-monitoring plan that can be expeditiously deployed in the event of a leak.

• States should review their authority to require greenhouse gas mitigation plans in the event of a leak.

Energy Reliability

 The shutdown of the Aliso Canyon facility increased the likelihood of regional electric generation shortages in Southern California this year. While communities were able to avoid electric curtailments this past summer, maintaining electric reliability without Aliso Canyon remains a concern heading into winter.

Other communities around the country could face similar concerns in the event of a leak in their region. Indeed, if such a leak led to a prolonged gas storage facility outage, the report found 12 of the nation’s underground gas storage facilities could affect 2 gigawatts or more of available electric generation capacity.

Concerning reliability, the task force recommends:

• Industry, federal and state agencies strengthen planning and coordination efforts to decrease the potential impacts of future prolonged disruptions of natural gas infrastructure.

• Industry, federal and state agencies should consider broader application of backup strategies to reduce reliability risks associated with the abrupt loss of natural gas supplies.

INGAA Concerns

Some findings of the report are troubling, according to Don Santa, president and CEO of the Interstate Natural Gas Association of America (INGAA), whose members transport more than 95% of the nation’s natural gas through a network of 200,000 miles of pipelines.

“INGAA is concerned that the task force finalized its recommendations prior to the completion of a root-cause analysis of the Aliso Canyon incident,” he said.

In particular, Santa said the report recommends that, except under limited circumstances, facility operators phase out “single point of failure” designs that contributed to the inability to swiftly control and repair the Aliso Canyon leak. It is also recommended that natural gas storage facility operators conduct risk assessments, develop and implement transition plans to address high-risk infrastructure, and apply robust procedures to maintain safety and reliability while the transition to modern well design standards is occurring.

“We are concerned by the task force’s recommendation that storage wells with ‘single barriers’ be transitioned to ‘double barriers’,” Santa said, adding that this prescriptive recommendation could affect the majority of U.S. natural gas storage wells and adversely affect customer service and reliability.

Santa said INGAA agreed with the recommendation that additional data collection and input from subject matter experts are necessary to inform future storage regulations. He also indicated INGAA looked forward to working with PHMSA and the DOE to support data collection and analysis moving forward.

Editor’s Note:  To review the report, Ensuring Safe and Reliable Underground Natural Gas Storage, visit www.eia.gov. For an overview of INGAA comments and recommendations, visit www.ingaa.org.